From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kyungmin Park Subject: [PATCH 1/2] mmc: core: new discard feature support at mmc v4.5 Date: Mon, 08 Aug 2011 11:11:25 +0900 Message-ID: <20110808021125.GA20321@july> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:22803 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752066Ab1HHCLb (ORCPT ); Sun, 7 Aug 2011 22:11:31 -0400 Received: from epcpsbgm1.samsung.com (mailout3.samsung.com [203.254.224.33]) by mailout3.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LPL00LXC7F0LLF0@mailout3.samsung.com> for linux-mmc@vger.kernel.org; Mon, 08 Aug 2011 11:11:30 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp2.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LPL00AKL7F67O@mmp2.samsung.com> for linux-mmc@vger.kernel.org; Mon, 08 Aug 2011 11:11:30 +0900 (KST) Content-disposition: inline Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org, Chris Ball Cc: jh80.chung@samsung.com, arnd@arndb.de From: Kyungmin Park At mmc v4.5, it supports the DISCARD feature (CMD38). It's different from trim and there's no check bit. currently it's only supported at v4.5. In trim mode, the controller can perform the actual erase at a convenient time. however, In discard, The controller can perform partial or full the actual erase at a convenient time. So in mmc v4.5, it's better to use the discard instead of trim. Signed-off-by: Kyungmin Park --- drivers/mmc/card/block.c | 4 +++- drivers/mmc/core/core.c | 14 ++++++++++++++ drivers/mmc/core/mmc.c | 4 ++++ include/linux/mmc/card.h | 3 +++ include/linux/mmc/core.h | 2 ++ 5 files changed, 26 insertions(+), 1 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 1ff5486..9649997 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -701,7 +701,9 @@ static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req) from = blk_rq_pos(req); nr = blk_rq_sectors(req); - if (mmc_can_trim(card)) + if (mmc_can_discard(card)) + arg = MMC_DISCARD_ARG; + else if (mmc_can_trim(card)) arg = MMC_TRIM_ARG; else arg = MMC_ERASE_ARG; diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index f091b43..c88fb57 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1586,10 +1586,24 @@ int mmc_can_trim(struct mmc_card *card) { if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN) return 1; + if (mmc_can_discard(card)) + return 1; return 0; } EXPORT_SYMBOL(mmc_can_trim); +int mmc_can_discard(struct mmc_card *card) +{ + /* + * As there's no way to detect the discard support bit at v4.5 + * use the s/w feature support filed. + */ + if (card->ext_csd.feature_support & MMC_DISCARD_FEATURE) + return 1; + return 0; +} +EXPORT_SYMBOL(mmc_can_discard); + int mmc_can_secure_erase_trim(struct mmc_card *card) { if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 5700b1c..2a356b7 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -405,6 +405,10 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd) if (card->ext_csd.rev >= 5) card->ext_csd.rel_param = ext_csd[EXT_CSD_WR_REL_PARAM]; + /* eMMC v4.5 or later */ + if (card->ext_csd.rev >= 6) + card->ext_csd.feature_support |= MMC_DISCARD_FEATURE; + if (ext_csd[EXT_CSD_ERASED_MEM_CONT]) card->erased_byte = 0xFF; else diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index b460fc2..d5d8c0d 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -77,6 +77,9 @@ struct mmc_ext_csd { u8 raw_sec_feature_support;/* 231 */ u8 raw_trim_mult; /* 232 */ u8 raw_sectors[4]; /* 212 - 4 bytes */ + +#define MMC_DISCARD_FEATURE BIT(0) /* CMD38 feature */ + unsigned int feature_support; }; struct sd_scr { diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index b8b1b7a..6118f10 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -146,6 +146,7 @@ extern int mmc_switch(struct mmc_card *, u8, u8, u8, unsigned int); #define MMC_ERASE_ARG 0x00000000 #define MMC_SECURE_ERASE_ARG 0x80000000 #define MMC_TRIM_ARG 0x00000001 +#define MMC_DISCARD_ARG 0x00000003 #define MMC_SECURE_TRIM1_ARG 0x80000001 #define MMC_SECURE_TRIM2_ARG 0x80008000 @@ -156,6 +157,7 @@ extern int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr, unsigned int arg); extern int mmc_can_erase(struct mmc_card *card); extern int mmc_can_trim(struct mmc_card *card); +extern int mmc_can_discard(struct mmc_card *card); extern int mmc_can_secure_erase_trim(struct mmc_card *card); extern int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from, unsigned int nr); -- 1.7.5.1.300.gc565c